Key
Facts about Water
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FRESHWATER
IS A SCARCE RESOURCE
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Water makes up 60 to 70 per cent (by weight) of all living
organisms and is essential for photosynthesis.
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The total amount of water on Earth barely changes from year
to year. The hydrological cycle of evaporation and precipitation
circulates the Earth’s water between the oceans, land
and the atmosphere.
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Water covers 75 per cent of the Earth’s surface —
97.5 per cent of that is salt water, only 2.5 per cent is
freshwater.
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Icecaps and glaciers hold 74 per cent of the world’s
freshwater. Almost all the rest is deep underground, or
locked in soils as moisture or permafrost. Only 0.3 per
cent of the world’s freshwater is found in rivers
or lakes.
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Less than one per cent of the world’s surface or below-ground
freshwater is accessible for human use.
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Within 25 years, half the world’s population could
have trouble finding enough freshwater for drinking and
irrigation.
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Currently, over 80 countries, representing 40 per cent of
the world’s people, are subject to serious water shortages.
Conditions may get worse in the next 50 years as populations
grow and as global warming disrupts rainfall patterns.
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A third of the world lives in water stressed areas where
consumption outstrips supply. West Asia faces the greatest
threat. Over 90 per cent of the region’s population
is experiencing severe water stress, with water consumption
exceeding 10 per cent of renewable freshwater resources.
FRESHWATER
IS ESSENTIAL FOR HEALTH
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Improved water management has brought enormous benefits
to people in developing countries. In the past 20 years,
over 2.4 billion people have gained access to safe water
supplies and 600 million to improved sanitation.
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Nevertheless, one in six people still have no regular access
to safe drinking water.
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More than twice that number (2.4 billion people) lack access
to adequate sanitation facilities.
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Those without access to adequate sanitation are the poorest
and most vulnerable. The problem is particularly severe
in remote rural and rapidly growing urban areas.
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In Africa, 300 million people—40 per cent of the population—live
without basic sanitation and hygiene, an increase of 70
million since 1990.
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As much as 90 per cent of waste water in developing countries
is discharged without treatment into rivers and streams.
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Unsanitary water, which provides a breeding ground for parasites,
amoebas and bacteria, damages the health of 1.2 billion
people a year.
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Water-borne diseases are responsible for 80 per cent of
illnesses and deaths in the developing world, killing a
child every eight seconds.
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Half the world’s hospital beds are occupied by people
suffering from water-borne diseases.
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Almost 40 per cent of the world’s population lives
within 60 kilometres of the coast. Disease and death related
to polluted coastal waters alone costs the global economy
US$16 billion a year.
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In southern Asia, between 1990 and 2000, 220 million people
benefited from improved access to freshwater and sanitation.
In the same period, the population grew by 222 million,
wiping out the gains that had been made.
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During the same period, in East Africa, the number of people
without sanitation doubled to 19 million.
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The cost of providing safe drinking water and proper sanitation
to everyone in the world by 2025 will be US$180 billion
a year, two to three times greater than present investments.
FRESHWATER IS A SHARED RESOURCE
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Rivers form a hydrological mosaic on the political map of
the world.
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There are an estimated 263 international river basins, which
cover 45.3 per cent of the Earth’s land surface area
(excluding Antarctica) and are home to more than half the
planet’s human population.
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One third of these 263 transboundary basins are shared by
more than two countries.
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Rarely do watershed boundaries coincide with administrative
boundaries.
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Many countries also share groundwater aquifers.
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Groundwater aquifers store as much as 98 per cent of accessible
freshwater supplies. They provide 50 per cent of global
drinking water, 40 per cent of industrial demands and 20
per cent of water for agriculture.
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On average, individual daily domestic use of freshwater
in developed countries is 10 times more than in developing
countries. In the UK the average person uses 135 litres
of water every day. In the developing world the average
person uses 10 litres.
FRESHWATER
IS ESSENTIAL FOR FOOD SECURITY
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Most of our freshwater is used to grow food.
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While the daily drinking water needs of every person is
approximately four litres, between 2,000 and 5,000 litres
of water are needed to produce an individual’s daily
food requirements.
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Agriculture accounts for over 80 per cent of world water
consumption.
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It is estimated that between 14 and 17 per cent more water
will be needed for irrigation by 2030 to feed the world’s
growing population.
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Sixty per cent of water used for irrigation is wasted.
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A 10 per cent improvement in irrigation efficiency could
double the drinking water supply for the poor.
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In Africa, more than 20 per cent of the population’s
protein comes from freshwater fisheries.
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Two hundred scientists in 50 countries have identified water
shortage as one of the two most worrying problems for the
new millennium (the other was climate change).
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Since 1950, global water use has more than tripled.
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On current trends, over the next 20 years humans will use
40 per cent more water than they do now.
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The number of people living in water-stressed countries
is projected to climb from the current 470 million to three
billion by 2025. Most of those people live in the developing
world.
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To achieve the 2015 targets for freshwater provision, water
supplies will have to reach an additional 1.5 billion people
in Africa, Asia, Latin America and the Caribbean.
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Nearly 200 million people in Africa are facing serious water
shortages. By 2025, nearly 230 million Africans will face
water scarcity, and 460 million will be living in water-stressed
countries.
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Water problems are more related to mismanagement than scarcity.
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Up to 50 per cent of urban water and 60 per cent of water
used in agriculture is wasted through leaks and evaporation.
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Logging and land conversion to accommodate human demand
has shrunk the world’s forests by half, contributing
to increased soil erosion and water scarcity.
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Between 300 and 400 million people worldwide live close
to and depend on wetlands.
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Wetlands act as highly efficient sewage treatment works,
absorbing chemicals and filtering pollutants and sediments.
Urban and industrial development has claimed half the world’s
wetlands.
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Sustainable development and poverty alleviation will only
be achieved through better management of and investment
in rivers and wetlands and the lands that drain into them.
Source: UNEP:
World Environment Day
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